Elementary Geometry

Irina Boyadzhiev, Jan 14, 2018

This book contains applet used for teaching geometry topics in classes for Elementary Teachers.


  • 1. Cavalieri's Principle
  • 2. Not Vertical Angles
  • 3. Vertical Angles
  • 4. Definition of a Circle
  • 5. The sum of the acute angles in a right triangle
  • 6. The Sum of the Interior Angles of Any Triangle
  • 7. The sum of the angles in Any Triangle
  • 8. The Sum of the Exterior Angles of Any Triangle
  • 9. Area of Triangles
  • 10. Congruent Triangles
  • 11. Parallelograms
  • 12. Properties of Parallelograms
  • 13. Line Symmetries and the Quadrilaterals
  • 14. Perimeter of a Rectangle
  • 15. Exterior Angles of Polygons
  • 16. Regular Pentagon and the Golden Ratio
  • 17. Angles in a Regular Polygon
  • 18. Art with Regular Polygons. Coloring.
  • 19. Errors in Measurement
  • 20. The midsegments divide any triangle in congruent triangles
  • 21. Triangles with Equal Area
  • 22. Pythagorean Theorem
  • 23. Circumference of a Circle and Pi
  • 24. Circumference of a Circle
  • 25. Explore the Area of a Circle
  • 26. Intersection of Circles and Spheres
  • 27. Copy of Volume of the Cuboid
  • 28. The Volume of the Sphere
  • 29. Prism
  • 30. Intersection of secants in a circle
  • 31. Maximum Area of a Rectangle if Fixed Perimeter
  • 32. Glide Reflection - Walking
  • 33. Rotational Symmetry
  • 34. Shearing Problem 6
  • 35. Shearing 7
  • 36. Cylinder
  • 37. Sections of Cylinders
  • 38. Net of a Cylinder
  • 39. Net of a Cone
  • 40. Conic Sections
  • 41. Exploring Sections of Cubes

1.

Cavalieri's Principle

This applet adds transfer of the slabs between the two stacks. The applet [color=#535353]was originally [/color][color=#535353]suggested [/color][color=#535353]by Steve Phelps - "[/color][color=#535353][u][url=http://www-beta.geogebra.org/m/3137147]Figure[/url] [/u][/color][color=#535353][u][url=http://www-beta.geogebra.org/m/3137147]6.7[/url] [/u][/color][url=http://www-beta.geogebra.org/m/3137147][color=#535353][u]Cavalieri's principle[/u][/color][/url][color=#535353]" [/color][color=#535353]and enhanced by Anthony C.M. OR -[/color][url=https://www.geogebra.org/material/simple/id/3139423][color=#666666][u]Cavalieri's[/u][/color][/url][url=https://www.geogebra.org/material/simple/id/3139423][color=#666666][u]Principle[/u][/color][/url][color=#535353]. [br]I would like to thank Anthony OR for contributing to the design of this applet.[/color]
– Irina Boyadzhiev

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